Microwave or like signals polarized in two mutually perpendicular planes can be subjected to phase shifting in a waveguide-type of device. Phase-shifting devices for this purpose can be used in telecommunications, more particularly as polarized feeds or receivers for antennas, preferably terrestrial antennas, operating in satellite systems for the purpose of aligning the polarization plane (with a polarizer of 180.degree.) received from the satellite with the polarization plane of the receivers, in the systems operating with linear polarization
They also are usable for transforming circular polarization into linear polarization and vice versa (90.degree. polarizer).
A phase shifter of this kind is preferably used in antenna illuminators (commonly known in the literature by the term "FEED").
The devices hitherto used for obtaining the desired phase shift employ the interposition of "irises" in a waveguide with orthogonal symmetry (square or circular guides).
These "irises" produce either a delaying or advancing effect for the waves of different polarizations.
It is known that a divider perpendicular to the axis in a waveguide of square or circular structure generates a capacitive effect for those polarizations which are perpendicular to the divider, while generating an inductive effect for a polarization wave parallel thereto.
These capacitive and inductive effects vary in degree with the frequency.
By combining these two effects and by choosing the right dimensions and number of lamellae it is possible to obtain the desired differential phase shift over a band of limited frequency range.
Such prior art polarizers cannot be effectively used for the transmission and the reception bands in satellite communication systems, which are known to be especially wide and distantly separated frequency bands.
With conventional polarizers, moreover, there is often the need for rotating the entire illumination system (such as is the case in linear polarizations) and/or to operate with separate phase shift modes in the different frequency bands.
In the first case the weight of the mechanical structure of the illumination system is increased and the alignment operation is slowed.
In the second case the separation circuit is highly complex, leading to insertion losses over the entire illumination system.